A method for dividing silicon wafer having a plurality of semiconductor chips into individual chips is such that the silicon wafer disposed on an adhesion sheet is diced, i.e., cut with using dicing cutter equipment having a dicing blade. At this time, a large amount of water jets toward the wafer so that heat generated by cutting the wafer is removed and radiated from the wafer to the water, a silicon chippage is flown and removed with the water, or the dicing blade is subsidized with the water.
Further, another dicing method is disclosed in Japanese Patent Application Publication No. 2001-176820. This method is used with a laser beam, which is irradiated on a silicon wafer so that the wafer is diced. At this time, cooling water is jetting on the wafer. However, a functional element, i.e., a semiconductor sensor, disposed on the wafer may be destroyed with the pressure of the cooling water or the surface tension of the cooling water, so that the device does not work correctly. Specifically, when the sensor is, for example, a capacitance type acceleration sensor, which has a movable portion, or the sensor has an air bridge wiring structure with an exposed member, which has weak mechanical strength and is exposed outside, the sensor may be destroyed easily.
In view of the above problem, further another dicing method is disclosed in Japanese Patent Application Publication No. 2000-223446. This method is used with a passivation cap disposed on a semiconductor wafer. The wafer with the passivation cap is diced, i.e., cut. The passivation cap protects the sensor from cooling water or dicing water, and is an adhesion sheet made of ultraviolet (i.e., UV) curable material. However, when the wafer with the passivation cap is cut and diced, the wafer is divided into a plurality of chips together with the passivation cap disposed on each chip. Therefore, after dicing, the passivation cap has to be removed from the chip individually. This process is necessitated to have much time and additional cost. Accordingly, each passivation cap on the chip is bonded together after dicing, so that each passivation cap is formed into a sheet again. Then, the passivation cap, i.e., the sheet is removed from the chip. However, this bonding process is necessitated to have much time and additional cost.